Your Digest for Saturday, Mar 09, 2024 07:59 PM


Actions of nitric oxide (NO)

EffectsOfNitricOxide.jpg

Concentric Vs. Eccentric LVH.

Concentric: normal mass but increased relative all thickening.
Eccentric: Increased mass but no increase in relative wall thickness.
Concentric occurs in AS.
Eccentric occurs in AR.
contentricVsEccentricHypertrophy.jpg
Source


Dead space

Total dead space (i.e physiological dead space) = anatomical dead space + alveolar dead space.

Anatomic dead space is Measured by Fowler's method.

The ratio of physiologic dead space to tidal volume is usually about 1/3. Source

Factors increasing dead space:
Source

Alveolar dead space is increased by :



loss of nitric oxide production, termed endothelial dysfunction, is the earliest event in the development of hypertension. Source


| Erosion | loss of Superficial epidermis => NO SCARRING | | |

Skin cancer

Squamous cell CA Basal Cell carcinoma Maligant melanoma
Chronic non healing ulcers or firm pink rapidly growing size Pearly, flesh coloured lesion with rolled up edges, central depression and telangiectasia. Occurs in sun exposed areas
AKA Rodent ulcer
ABCDE lesions
malignantMelanoma.png
Rapidly growing Slow growing. Arises from keratinocytes.
"only rarely a threat to life"
The most dangerous skin cancer; use ABCDE as warning signs. Arises from melanocytes which are neural crest derivatives
Metastasis is uncommon. (upto 5%) Metastasis common. (Nodes and distant). 5 year survival for nodal mestastasis is only 10%.
RF: Sunlight, smoking, chronic ulcers, melanomaFeatures.png
Occurs on areas of ⬆ sun exposure
Rx: Excission with 4mm margins.
Mohs micrographic surgery in high risk /
cosmetically sensitive areas.
Poor prognosis
if > 20mm wide or
> 4mm deep

Actinic keratosis

Actinic keratosis is a premalignant lesion which can transform into squamous cell carcinoma.
The image below shows "Malignant transformation of actinic keratoses to squamous cell carcinoma"
actinicKeratosisTransformationSQC.png


Inhibition : Somatostatin


[!INFO] However, Sri Lankan guidelines recommend starting with dual low dose combination.

Causes of isolated systolic hypertension

Pharmacology of antihypertensives

AssessmentOfResistantHypertension.png
Patients with resistant hypertension are more likely to have secondary causes. (which may contribute atleast partly).
CausesOfSecondayHypertension.png

[!INFO] "Renal parenchymal diseases"
The most common renal parenchymal diseases leading to secondary hypertension include

  1. diabetic nephropathy, chronic glomerulonephritis, glomerulosclerosis, and autosomal dominant polycystic kidney disease (ADPKD)
  2. and all these disorders result in chronic kidney disease (CKD). Source
  3. HypertensionCKD.png

Clinical entities to consider in secondary causes for hypertension:

  1. Renal parenchymal disease
  2. Endocrine disease
  3. Reno-vascular hypertension
  4. Vascular and other
    1. Coarctation of the aorta
    2. OSA

There is a large overlap with 'causes of secondary hypertension'.
Causes of resistant hypertension
5. OCP


3 options with varying disadvantages:


High fevers with delirium.

Early in disease course, fever occurs at irregular intervals each day.
Later in the course of infection, rupture of infected red cells can become synchronous following concurrent schizont rupture and release of merozoites from erythrocytes.

Febrile paroxysms may occur every other day (tertial) for P. vivax, P. ovale, and P. falciparum and every third day for P.malariae. Paroxysms occurring at regular intervals are more common in the setting of infection due to P. vivax or P. ovale than P. falciparum..

Fever in falciparum is usually irregular - Source
[!TIP] Mnemonic: "m" = 3 lines. P malariae causes fever every 3rd day.

Labs:

Chronology of malaria

Severe paracitaemia = > 5% of cells area affected.
90% of severe malaria is due to falciparum. However, vivax and knowlesi can cause severe malaria. - UpToDate

Manifestations

Liver dysfunction does occur in malaria but wasn't included in the list above. (??because it's common and doesn't occur only in severe malaria)

Treatment for severe malaria is IV or IM Artesunate


📑📑Video
- causes constriction - miosis; begins at the Edinger-Westphal nucleus near the occulomotor nerve nucleus. The fibers enter the orbit with CNIII nerve fibers and ultimately synapse at the cilliary ganglion.


Action potentials

[!INFO] Inactivated sodium channels
In the aboslute refractor periods the sodium channels are in the "inactivated" state (not the closed state)
When the relative refactor period begins, the sodium channels are starting to return to their closed state.
mnemonic: the "closed state" means the channels are "primed" to fire.

Apparently, ARP lasts into the first 1/3 of the repolarization phase: Source-YouTube

absoluteAndRelativeRefractoryPeriods.png
MRI is the modality of choice for delineating perianal fistulae in Crohn's disease.


- *encystation* for continuation of the infective cycle occurs in the large intestine. 
- 90% of infected individuals show asymptomatic colonization but they still shed infective cysts. 

Meropenem penetration: Meropenem is not absorbed after oral administration. It penetrates well into most body fluids and tissues, including CSF, achieving concentrations matching or exceeding those required to inhibit most susceptible bacteria


| All are neurotoxic except | hump nosed and saw scaled viper |
| Local swelling and necrosis NOT seen | Kraits and sea snakes |

[!TIP] HNV => VICC; but no overt bleeding, plantations, severe local pain+, Acut kidney injury

VICC

VICC is NOT the same as DIC. Source
In contrast to DICC, VICC has the following.


- Non shockable rhythm: ***Adrenaline 1mg ASAP*.** **(10ml of 1:10,000 IV or 1ml of1:1000 IV)**